Revert "iommu/arm-smmu-v3: Abort all transactions if SMMU is enabled in kdump kernel"

euler inclusion
category: bugfix
bugzilla: 5452
CVE: NA

This patchset is add a kernel parameter to avoid kdump
problem on Hi1620ES. It will be revert when we have better
solution on Hi1620CS.

[PATCH 1/4] Revert "iommu/arm-smmu-v3: Abort all transactions if SMMU is enabled in kdump kernel"
[PATCH 2/4] device: add device_shutdown_one() helper
[PATCH 3/4] device: add device_shutdown_by_driver() helper
[PATCH 4/4] kexec: add kexec_device_shutdown()

------------------------------------------------

This reverts commit b63b3439.
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/iommu/arm-smmu-v3.c

@@ -24,7 +24,6 @@
 #include <linux/acpi_iort.h>
 #include <linux/bitfield.h>
 #include <linux/bitops.h>
-#include <linux/crash_dump.h>
 #include <linux/delay.h>
 #include <linux/dma-iommu.h>
 #include <linux/err.h>
@@ -2244,12 +2243,8 @@ static int arm_smmu_update_gbpa(struct arm_smmu_device *smmu, u32 set, u32 clr)
 	reg &= ~clr;
 	reg |= set;
 	writel_relaxed(reg | GBPA_UPDATE, gbpa);
-	ret = readl_relaxed_poll_timeout(gbpa, reg, !(reg & GBPA_UPDATE),
-					 1, ARM_SMMU_POLL_TIMEOUT_US);
-
-	if (ret)
-		dev_err(smmu->dev, "GBPA not responding to update\n");
-	return ret;
+	return readl_relaxed_poll_timeout(gbpa, reg, !(reg & GBPA_UPDATE),
+					  1, ARM_SMMU_POLL_TIMEOUT_US);
 }
 
 static void arm_smmu_free_msis(void *data)
@@ -2429,15 +2424,8 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)
 
 	/* Clear CR0 and sync (disables SMMU and queue processing) */
 	reg = readl_relaxed(smmu->base + ARM_SMMU_CR0);
-	if (reg & CR0_SMMUEN) {
-		if (is_kdump_kernel()) {
-			arm_smmu_update_gbpa(smmu, GBPA_ABORT, 0);
-			arm_smmu_device_disable(smmu);
-			return -EBUSY;
-		}
-
+	if (reg & CR0_SMMUEN)
 		dev_warn(smmu->dev, "SMMU currently enabled! Resetting...\n");
-	}
 
 	ret = arm_smmu_device_disable(smmu);
 	if (ret)
@@ -2535,8 +2523,10 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)
 		enables |= CR0_SMMUEN;
 	} else {
 		ret = arm_smmu_update_gbpa(smmu, 0, GBPA_ABORT);
-		if (ret)
+		if (ret) {
+			dev_err(smmu->dev, "GBPA not responding to update\n");
 			return ret;
+		}
 	}
 	ret = arm_smmu_write_reg_sync(smmu, enables, ARM_SMMU_CR0,
 				      ARM_SMMU_CR0ACK);